Emily - Quizizz Practice

When the car moves AWAY from you, its horn seems...

• Low pitched
• High pitched
• Normal

When an ambulance move TOWARD you it sounds ________ pitched. 

• high
• low
• medium

The Doppler effect is seen when a wave-making source moves toward an observer. 

• True
• False

What can you tell about this object's motion?

• Moving to the North (up).
• Moving to the South (down). 
• Moving to the West (left). 
• Moving to the East (right). 

What is the Doppler Effect?

• A change in frequency due to the relative motion of a wave source and an observer

• When a wave overlaps with another wave

• When a wave bounces off of another object

• When a wave bends due to traveling through a different medium

You stand on the sidewalk next to the street. A fire truck is moving towards you. The frequency of the siren on the fire truck is 600 Hz.

What should you hear?

• Frequency higher than 600 Hz

• Frequency lower than 600 Hz

• Exactly 600 Hz

• No sound, silence.

You stand on the sidewalk next to the street. A fire truck is away from you. The frequency of the siren on the fire truck is 600 Hz.

What should you hear?

• Frequency higher than 600 Hz

• Frequency lower than 600 Hz

• Exactly 600 Hz

• No sound, silence.

A car moves at 20 m/s away from a whistle. The whistle is stationary. The whistle makes a sound with a frequency of 500 Hz. The speed of sound in air is 330 m/s.

What is the frequency observed by the driver of the car?

• 530 Hz

• 470 Hz

• 520 Hz

• 480 Hz

A fire truck is moving away from you. The fire truck moves with a speed of 30 m/s. You are motionless. The siren on the fire truck makes a sound with a frequency of 700 Hz. The speed of sound in air is 350 m/s.

What frequency will you hear?

• 765 Hz

• 730 Hz

• 660 Hz

• 645 Hz

You cannot hear ultrasound because it is:

• too loud
• too quiet
• high frequency
• low frequency